Always use extern crate std in cranelift-frontend

cranelift/frontend/src/frontend.rs

@@ -13,7 +13,7 @@ use cranelift_codegen::ir::{
 };
 use cranelift_codegen::isa::{TargetFrontendConfig, TargetIsa};
 use cranelift_codegen::packed_option::PackedOption;
-use std::vec::Vec;
+use alloc::vec::Vec;
 
 /// Structure used for translating a series of functions into Cranelift IR.
 ///
@@ -899,7 +899,7 @@ mod tests {
     use cranelift_codegen::isa::CallConv;
     use cranelift_codegen::settings;
     use cranelift_codegen::verifier::verify_function;
-    use std::string::ToString;
+    use alloc::string::ToString;
 
     fn sample_function(lazy_seal: bool) {
         let mut sig = Signature::new(CallConv::SystemV);

cranelift/frontend/src/lib.rs

@@ -183,9 +183,8 @@
 )]
 #![no_std]
 
-#[cfg(not(feature = "std"))]
-#[macro_use]
-extern crate alloc as std;
+extern crate alloc;
+
 #[cfg(feature = "std")]
 #[macro_use]
 extern crate std;

cranelift/frontend/src/ssa.rs

@@ -17,7 +17,7 @@ use cranelift_codegen::ir::{Ebb, Function, Inst, InstBuilder, InstructionData, T
 use cranelift_codegen::packed_option::PackedOption;
 use cranelift_codegen::packed_option::ReservedValue;
 use smallvec::SmallVec;
-use std::vec::Vec;
+use alloc::vec::Vec;
 
 /// Structure containing the data relevant the construction of SSA for a given function.
 ///

cranelift/frontend/src/switch.rs

@@ -3,7 +3,7 @@ use crate::frontend::FunctionBuilder;
 use cranelift_codegen::ir::condcodes::IntCC;
 use cranelift_codegen::ir::*;
 use log::debug;
-use std::vec::Vec;
+use alloc::vec::Vec;
 
 type EntryIndex = u64;
 
@@ -291,7 +291,7 @@ mod tests {
     use super::*;
     use crate::frontend::FunctionBuilderContext;
     use cranelift_codegen::ir::Function;
-    use std::string::ToString;
+    use alloc::string::ToString;
 
     macro_rules! setup {
         ($default:expr, [$($index:expr,)*]) => {{